Synthetic drug use，sexual behavior and associated factors among men who have sex with men in Shanghai / 上海预防医学

Objective:To understand the status of synthetic drug use， high-risk sexual behavior and associated factors among men who have sex with men （MSM） in Shanghai. Methods:MSM subjects were recruited， by a team of non-governmental organizations （NGO）， at MSM places and voluntary counseling and testing clinics from May to December 2018. The subjects completed a self-administered questionnaire survey on social-demographic， ways to make friends， synthetic drug use， high-risk sexual behavior， and HIV/STD testing history. They also received tests of HIV and syphilis. According to the use of synthetic drugs， they were divided into user group and non-user group. Results:A total of 209 subjects were recruited. Among them， 43.1% （90/209） used at least one synthetic drug. 81.3% （170/209） of MSM used internet dating software. The proportion of synthetic drug use was higher among the subjects in 30-34 age group， residence registered in other provinces， with university degree or above， occupation of cadres and staff members， monthly income of more than 10 000 yuan， making friends through gay bars， and acquaintance with male partners. The registered residence in other provinces （OR=3.006） and making friends through gay bars （OR=3.588） were independent factors. The top three synthetic drugs were Rush （90.0%， 81/90）， Viagra （8.9%， 8/90） and “capsule 0” （7.8%， 7/90）. The proportion of having sex after using synthetic drugs was 89.5% （17/19）. The frequency of high-risk sexual behaviors such as oral sex， anal sex without condom and group sex was once a day per person on average. Conclusion:The use of synthetic drugs is prevalent among MSM， and the frequency of high-risk sexual behaviors after use is high. Warning education on the dangers of synthetic drug use and mobilization for HIV testing should be carried out with the help of new media technology. Special attention should be paid to MSM people in high-income occupations and gay bars.

Two New Species of Placolecis (Lichenized Ascomycota) from China

Two new species of the lichen genus Placolecis are discovered in China, namely P. kunmingensis An. C. Yin & Li S. Wang and P. sublaevis An. C. Yin & Li S. Wang. The new combination P. loekoesiana (S.Y. Kondr., Farkas, J.J. Woo & Hur) An. C. Yin is proposed. Placolecis kunmingensis is characterized by having simple, spherical or ellipsoid, hyaline spores, and pear-shaped pycnidia; while P. sublaevis can be distinguished by its thallus forming larger aggregations with slightly flattened lobes at the thallus margin, and urn-shaped pycnidia. Descriptions, a phylogenetic tree and a key are provided for all the known Placolecis species in China.

Acceptance of Chemo-prophylaxis for Latent Tuberculosis Infection among High School/College Student Contacts of Tuberculosis Patients in Shanghai, China / 生物医学与环境科学（英文）

Student contacts of tuberculosis (TB) cases are susceptible to latent tuberculosis infection (LTBI), and chemo-prophylaxis can reduce the risk of active TB among them. This study aimed to assess the acceptance of chemo-prophylaxis for LTBI among students, and their concerns regarding TB and its preventive treatment. A total of 560 students contacts were included in the investigation. The extent of contact was categorized from high to low (4 levels) with 12.9% of the students being close contacts. About 87.0% of the students were willing to receive chemo-prophylaxis if diagnosed with, LTBI, whereas 73 students declined. Students with a higher level of knowledge about TB (aOR = 1.11) or close contact with TB patients (aOR = 4.30) were more likely to accept treatment. To conclude, education regarding TB transmission is necessary. Moreover, LTBI detection should be integrated into the current school-based TB contact investigation.

AIDS discrimination survey among AIDS medical staff in Xuhui district in Shanghai / 上海预防医学

[Objective] To investigate the discrimination status among AIDS medical staff towards HIV/AIDS patients in XuHui district and analyze the factors influencing the discriminary attitude and be -havior will of medical staff . [ Methods] A total of 133 AIDS medical staff from 31 medical institutions were investigated by means of a self -designed questionnaire in Xuhui District . [ Results] In the atti-tude to PLWHA, the terms in the questionnaire with the highest and the lowest discrimination score were“people living with HIV should be sent to infection hospital” and “the privacy of people living with HIV should be respected”, whose scores were 1.59 and 0.03 points.In the behavior will to PLWHA, the terms with the highest and the lowest discrimination score were “not to shop from people living with HIV” and“willing to communicate with acquaintances infected with HIV”, whose scores were 1.05 and 0.48 points. The difference in discrimination score was female >male and clinical post >test post >healthcare post . [ Conclusion] Gender and occupation are the main factors affecting discrimination scores .The attitude and behavior will to PLWHA are inconsistent in some places .Measures should be taken to reduce PLWHA discrimination , such as effectively implementing the “AIDS prevention and control regulation”, strengthe-ning the occupation moral training of medical staff , and enhancing the occupation protection policy and training.

The impact of incorrectly-measured variables when mixed with precisely measured variables on the study of validity in epidemiological research / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the impact of measurement error on the associated effects under the incorrectly-measured variables when mixed with precisely measured variables.</p><p><b>METHODS</b>Based on the functions of measurement error, correlation of incorrectly-measured predictors and precisely measured explanatory variables, number of precisely measured explanatory variables and associated effect, the 'R Project for Statistical Computing' method is used to analyze the impact of measurement on the validity of a study.</p><p><b>RESULTS</b>Under the scenario that the continuous response Y and the continuous explanatory Z are precisely measured but the continuous predictor X is incorrectly-measured, when focusing on inference about the effect of X on Y, the non-differential measurement error always makes the value of estimated effect less than the actual value, and the attenuation effect of measurement error more closely worsens the correlation of X and Z. Under a misclassification dichotomous predictor X with an additional precisely measured explanatory variable Z and focusing on inference about the effect of X on Y, the misclassification bias is not only related to the sensitivity and specificity of exposure measurement, but also to the correlation between X and Z and exposure proportion of X. The attenuation factor (AF) decreases gradually with the increasing correlation between X and Z. For instance, in the p = 0.5 scenario, AF is 1.419, and the estimated effect of dichotomous predictor X on continuous response Y is more than the actual effect. When it increases to 0.9, AF is 0.474, the estimated effect becomes less than the true effect.</p><p><b>CONCLUSION</b>In the studies of the impact of measurement error in linear regression with additional precisely measured explanatory variables, the impact of measurement error on the associated effect is relatively complex, suggesting that it is necessary to control and to assess the measurement error bias in order to correctly interpret the results of a study.</p>

Study on the impact of exposure misclassification on the validity of a study / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the impact of misclassification in binary explanatory variables on the effects associated with 'exposure-disease'.</p><p><b>METHODS</b>Based upon the functions of probabilities on misclassification, effects of association and proportions of exposure, the 'R Project for Statistical Computing' method was used to analyze the impact of misclassification on the validity of a study.</p><p><b>RESULTS</b>To the linear model case, the effect of nondifferential misclassification serves as an attenuating bias. When r = 0.5, the bias is symmetric in both sensitivity and specificity but when r is not equal to 0.5, the bias is not symmetric in sensitivity and specificity. When misclassification is nondifferential, estimated odds ratio tends to be 1 while the exposure prevalence in the control tends to be 0 or 1. Bias seems to be very complex in differential misclassification than in nondifferential misclassification that can make OR tend to or be away from the null value.</p><p><b>CONCLUSION</b>The impact of exposure misclassification on the effect associated with exposure--disease is complicated, hence necessary to understand, to control, and to assess bias of misclassification in order to correctly interpret the results of a study.</p>

A study on the screening of high-risk population of schistosomiasis using a quick inquiry discriminant method during the years of disasters / 中华流行病学杂志

<p><b>OBJECTIVE</b>To seek a rapid, simple, but effective inquiry method for screening high risk population challenged by schistosomiasis.</p><p><b>METHODS</b>Two embankment collapsed villages were selected in schistosomiasis epidemic area in Dongting Lake. Information on water exposure was collected through a retrospective study. Data was analyzed by stepwise discriminant analysis.</p><p><b>RESULTS</b>A Fisher's function was established by stepwise discriminant analysis which including 5 variables out of 18. Two hundred and forty-six individuals were discriminated by the function with accuracy, sensitivity and specificity of predicting their current infection status with the results of 87.4%, 84.1% and 89.0% respectively.</p><p><b>CONCLUSION</b>The inquiry method might serve as simple, rapid, economic and effective tool for diagnosis in screening high risk population challenged by schistosomiasis in lake communities.</p>